Construction industry best seller

What constitutes a ‘best selling’ book in the construction industry?
If my intent is to share what I have learned and my ideas rather than make money from my books, and I have given away 1,500 copies of my first co-authored book, “21st Century People Leadership”, is that a ‘best seller’?

When a busy director sends me an email saying, “Dave, loved your book, could you send six copies, because my team really needs to read it’, and I send them, free of charge, am I behaving like a ‘best-selling author’?

Likewise, I think my second book, “We need to talk about collaboration”, has been downloaded or forwarded to about 2,000 construction industry professionals. Does that make it a ‘best seller’?

I’m not bothered about either of them being a ‘best seller’, though if they were then maybe I’d be able to give more copies away and spread my ideas and value more widely.

Anybody know how many copies you have to shift for a book to be a best seller?

Ps. If you would like a copy of either, free, just visit www.dsabuilding.co.uk. Happy reading!